Designing and manufacturing vehicle floor trays

ABSTRACT

A vehicle floor tray is molded from a multiple extrusion polymer sheet such that it has high shear and tensile strength, an acceptable degree of stiffness and a high coefficient of friction on its upper surface. The floor tray design is digitally fitted to a foot well of a particular vehicle such that large areas of at least two upstanding walls of the tray depart from respective surfaces of the foot well by no more than an eighth of an inch.

RELATED APPLICATIONS

This application is a continuation of copending U.S. Nonprovisionalapplication Ser. No. 11/463,203 filed on Aug. 8, 2006, which is in turna division of U.S. Nonprovisional application Ser. No. 10/976,441 filedon Oct. 29, 2004, now U.S. Pat. No. 7,316,847. The disclosures anddrawings of those applications are fully incorporated by referenceherein.

BACKGROUND OF THE INVENTION

Motor vehicles are almost always operated in the out of doors and arefrequently parked there. It is therefore very common for their occupantsto have wet or muddy feet—if the occupants have not just finished anoutdoor activity, at least they have had to walk across a possibly wet,snowy or muddy surface to access their vehicles. For decades, therefore,vehicle owners have been attempting to protect the enclosed interiors oftheir vehicles (cars, trucks, SUVs) from what they themselves track intothem. The conventional solution to this has been to provide a vehiclefloor mat which may be periodically removed by the owner and cleaned.

Human beings have a tendency to move their feet around, and foot motionis an absolute requirement in operating most vehicles. This has caused aproblem, in that the occupants of a vehicle have a tendency to pusharound the floor mats with their feet. The floor mats end up not beingcentered on the area protected, or pushed up so as to occlude the gas,brake or clutch pedals, or bunched up or folded over—all undesirableconditions. One objective of floor mat manufacturers has therefore beento provide a floor mat that will stay put and which will not adverselyaffect vehicle operation.

The foot wells of cars, trucks and SUVs vary in size in shape from onemodel of vehicle to the next. Floor mat manufacturers have noticed thatfloor mats which at least approximately conform to the shape of thebottom surface of the foot well stay in place better and offer moreprotection. It is also common for such floor mats, where provided forfront seat foot wells, to have portions which are meant to lie againstthe firewalls or front surfaces of the foot wells. Even as so extendedit is not too hard to provide a floor mat of flexible material that willapproximately conform to these two surfaces, as the designer only has tomark a two-dimensional periphery of the mat in providing one which willfit reasonably well.

More recently, vehicle floor trays have come onto the market. Mostfront-seat vehicle foot wells are actually three-dimensional concaveshapes, typically with complex curved surfaces. Floor trays havesidewalls that offer enhanced protection to the surfaces surrounding thevehicle floor, as might be needed against wearers with very muddy orsnowy shoes. Conventional vehicle floor trays try to fit into thesethree-dimensional cavities, but so far their fit to the surfaces thatthey are supposed to protect has been less than optimum. A conventionalvehicle floor tray is typically molded of a single-ply rubber or plasticmaterial, exhibits enough stiffness to retain a three-dimensional shape,but is also at least somewhat flexible. Fitting such a tray to thecomplex three-dimensional surface of a vehicle foot well has proven tobe difficult, and the products currently in the marketplace have limitedconsumer acceptance because of their loose fit inside the foot well.There is often, and in many places, a considerable space between theexterior wall of these conventional trays and the interior surface ofthe foot well. This causes the wall to noticeably deform when theoccupant's foot contacts it. Vehicle owners have a tendency to dislikefloor trays which rattle, deform, shift and flop about. A need thereforepersists for a floor tray that will have a more exact fit to the vehiclefoot well for which it is provided, that stays in place once it isinstalled, and that provides a more solid and certain feel to theoccupants' feet.

Some vehicle floor mats that are now on the market have fluid reservoirsbuilt into them. Particularly in cold or wet climates, dirty water has atendency to be shed onto the floor mat, where it persists until itevaporates. If there is enough of it, it will leak off of the floor matand stain the carpeting of the foot well that the mat was meant toprotect. These reservoirs typically are recessed areas in the mats thatprovide the mats with an enhanced ability to retain snow-melt and thelike, until the water evaporates or can be disposed of by the vehicleowner or user. One advanced design places treads in the middle of thereservoir, such that the feet of the occupant are held above any fluidthat the reservoir collects. But including such a reservoir within afloor tray that otherwise has an acceptable fit to the surface of avehicle foot well has not yet been done, since there are problems inincorporating a three-dimensional liquid-holding vessel into a productthat ideally conforms, on its lower surface, to the surface of the footwell. Further, a reservoir which collects drip water from a largesurface, such as a vehicle floor tray, will exhibit more problems inkeeping the collected fluid from sloshing about in a moving vehicle.

Conventional vehicle floor mats and trays are molded from a singlerubber or plastic material. The selection of this material is controlledby its cost, its resistance to shear forces, its tensile strength, itsabrasion resistance, its ability to conform to the surface of thevehicle foot well, its sound-deadening properties and how slippery ornonslippery it is relative to the occupants' feet, with nonslipperiness(having a relatively high coefficient of friction) being advantageous.Often the designer must make tradeoffs among these different designconstraints in specifying the material from which the tray or mat is tobe made.

SUMMARY OF THE INVENTION

According to one aspect of the invention, there is provided a vehiclefloor cover, mat or tray which is removably installable by a consumerand which is formed of at least three layers that are bonded together,preferably by coextrusion. The three layers include a central layerwhose composition is distinct from a bottom layer and a top layer.Preferably, all three layers are formed of thermoplastic polymermaterials. In another aspect of the invention, the top layer exhibits akinetic coefficient of friction with respect to a sample meant toemulate a typical shoe outsole (neoprene rubber, Shore A Durometer 60)of at least about 0.82.

Preferably, a major portion of the central layer is a polyolefin. Morepreferably, the polyolefin is either a polypropylene or a polyethylene.Most preferably, the polyolefin is high molecular weight polyethylene(HMPE) as herein defined. In an alternative embodiment, the centrallayer can be a styrene-acrylonitrile copolymer (SAN) or anacrylonitrile-butadiene-styrene (ABS) polymer blend.

Preferably, a major portion of the top layer is a thermoplasticelastomer, such as one of the proprietary compositions sold under thetrademarks SANTOPRENE®, GEOLAST® and VYRAM®. VYRAM® is particularlypreferred. In another embodiment, a major portion of the top layer canbe an ABS polymer blend. Where ABS is used in both the top and centrallayers, it is preferred that the amount of the polybutadiene phase inthe top layer be greater than the amount of this phase in the centrallayer.

It is further preferred that a major portion of the bottom layerlikewise be a thermoplastic elastomer, and conveniently it can be, butdoes not have to be, of the same composition as the major portion of thetop layer.

Preferably one or more of the layers is actually a polymer blend, inwhich a minor portion is preselected for its coextrusion compatibilitywith the adjacent layer(s). Thus, a minor portion of the top and bottomlayers can consist of a polyolefin, while a minor portion of the centrallayer can consist of a thermoplastic elastomer. In each case, it ispreferred that the minor portion be no more than about one part in fourby weight of each layer, or a weight ratio of 1:3. Where all threelayers are preselected to be ABS blends, the amount of polybutadienepreferably is decreased in the central layer relative to the top andbottom layers.

While the preferred embodiment of the vehicle floor cover consists ofthree integral layers, any one of the recited layers can in fact be madeup of two or more sublayers, such that the total number of sublayers inthe resultant mat or tray can exceed three.

In another embodiment, the thermoplastic elastomer constituent of thetop, central and/or bottom layers described above can be replaced with anatural or synthetic rubber, including styrene butadiene rubber,butadiene rubber, acrylonitrile butadiene rubber (NBR) or ethylenepropylene rubber (EPDM).

According to a related aspect of the invention, a vehicle floor cover isprovided that has three layers bonded together, preferably bycoextrusion. Major portions of the top and bottom layer consist ofthermoplastic elastomer(s). The top and bottom layers have compositionsdistinct from the central layer, which can be chosen for its relativelylow expense. It is preferred that a major portion of the central layerbe a polyolefin and that major portions of the top and bottom layers beone or more thermoplastic elastomers. The polyolefin may be selectedfrom the group consisting of polypropylene and polyethylene, andpreferably is a high molecular weight polyethylene (HMPE). Thethermoplastic elastomer can, for example, be SANTOPRENE®, GEOLAST® orVYRAM®, with VYRAM® being particularly preferred. It is also preferredthat each of the layers be a polymer blend, with a minor portion of eachlayer being chosen for its coextrusion compatibility with adjacentlayers. For example, the top and bottom layers can consist of a 3:1weight ratio of VYRAM®/HMPE, and the central layer of a 3:1 weight ratioof HMPE/VYRAM®.

In an embodiment alternative to the one above, the top and bottom layerscan consist of ABS polymer blends and the central layer can consist ofSAN or an ABS in which the polybutadiene phase is present in a smallerconcentration than in the top and bottom layers.

In yet another embodiment, the thermoplastic elastomer recited in thisaspect of the invention may be replaced with a natural or syntheticrubber, such as styrene butadiene rubber (SBR), butadiene rubber,acrylonitrile butadiene rubber (NBR) or ethylene propylene rubber(EPDM).

In a further aspect of the invention, a vehicle floor tray or mataccording to the invention is made of three layers, wherein a top layerand a bottom layer have composition(s) distinct from the central layer,and wherein at least one of the shear strength per cross-sectional area,tensile strength per cross-sectional area and stiffness percross-sectional area is greater than any one of the layers from whichthe tray or mat is composed. It has been found that a triextrudedvehicle mat or floor tray according to the invention exhibits a tensilestrength at yield, a tensile stress at break, a tensile modulus, a shearstrength and a flexural modulus (stiffness) which are superior to eithera polyolefin-dominated single extrusion or a thermoplasticelastomer-dominated single extrusion. The triextrusion tray demonstratesthese enhanced physical properties while at the same time affording anenhanced coefficient of friction to the feet of the occupant andimproved tactile properties. By presenting such a surface to the shoe ofthe driver or passenger, the footing of the driver or passenger will bemore sure and comfortable.

In a further aspect of the invention, a vehicle foot well tray isprovided as a part of a system that has the vehicle foot well as itsother main component. The tray has a greatly enhanced conformance to thesurface of the vehicle foot well for which it is provided. At least twoupstanding walls of the tray, both extending from the tray floor to atop margin, conform to respective surfaces of the vehicle foot well suchthat at least within that one-third of the area of the outer surface ofthese upstanding walls of the tray which is adjacent the top margin, 90%of that top third area departs by no more than about one-eighth of aninch from the foot well surfaces to which they mate. These upstandingtray surfaces may be opposed surfaces or adjacent surfaces, andpreferably are both. In a preferred embodiment, the tray departs from adoor sill surface of the vehicle foot well, and/or a sill curve of thevehicle foot well, by about 0.025 inches. The upstanding sidewalls ofthe floor tray conform to the foot well surfaces which they cover, evenwhere such foot well surfaces present both concave and convex surfaceelements.

In a still further aspect of the invention, a top margin of a vehiclefloor tray is substantially coplanar on at least two upstandingsidewalls thereof. Preferably, the top margin of the tray issubstantially coplanar through three or even four continuous upstandingsidewalls. This eases the design of the floor tray, increases hoopstrength and assures that all upstanding surfaces of the vehicle footwell will receive adequate protection from muddy footwear. In aparticularly preferred embodiment, the plane of the top margin isforwardly and upwardly tilted relative to a horizontal floor. Thisprovides enhanced protection to the vehicle foot well precisely in theplace where muddy footwear are likely to be, near the accelerator, brakeand clutch pedals or the firewall. In a preferred embodiment, the trayis at least five inches deep at its deepest part.

In a further aspect of the invention, the above mentioned tighttolerances are made possible by a novel vehicle floor tray manufacturingmethod. In a first step according to the invention, points on a surfaceof the vehicle foot well are digitally measured with a coordinatemeasuring machine (CMM). These points are stored in a computer memory. Afoot well surface is generated which includes these points, preferablyby connecting linear groups of the points together by using B-splines,and lofting between the B-splines to create areal portions of the footwell surface. Using this typically complex three-dimensional,predominately concave surface, which may have several concavely andconvexly curved portions, a corresponding substantially convex outerfloor tray surface is built up such that in many regions, the distancebetween the outer surface of the tray and the surface of the foot wellis no more than about one eighth of an inch, insuring a snug fit.

In one embodiment of the invention, a reservoir is incorporated into thetray floor as a collection and evaporation area for drip water from thefeet and legs of the occupant. Combination baffles/treads are providedin the reservoir to impede lateral movement of the collected fluid.Longitudinal and transverse portions of these baffles are joinedtogether. Channels are cut into another portion of the central area ofthe tray to direct fluid to the reservoir, such that the bottom of thechannels is beneath a general tray floor surface but above the bottom ofthe reservoir. In a preferred driver's side embodiment, the channels areomitted from a portion of the floor tray upper surface to leave a blankspace where the driver's heel will rest when operating the gas and brakepedals.

BRIEF DESCRIPTION OF THE DRAWINGS

Further aspects of the invention and their advantages can be discernedin the following detailed description, in which like characters denotelike parts and in which:

FIG. 1 is an isometric view of one embodiment of a vehicle floor trayaccording to the invention;

FIG. 2 is a top view of the floor tray illustrated in FIG. 1;

FIG. 3 is an isometric and transverse sectional view of the floor trayseen in FIGS. 1 and 2, the section taken substantially along line 3-3 ofFIG. 2;

FIG. 4 is an isometric and longitudinal sectional view of the floor trayshown in FIGS. 1 and 2, the section taken substantially along line 4-4of FIG. 2;

FIG. 5 is a side view of the tray illustrated in FIG. 1, taken from theouter side;

FIG. 6 is a highly magnified sectional view of a vehicle floor tray,showing triextruded layers;

FIG. 7 is a schematic block diagram showing steps in a design andmanufacturing process according to the invention; and

FIG. 8 is an isometric and schematic view of a digitally acquiredvehicle foot well floor surface from which the illustrated floor traywas made;

FIG. 9 is a partly transverse sectional, partly isometric view of boththe floor tray illustrated in FIG. 2 and the vehicle foot well surfaceillustrated in FIG. 8, taken substantially along line 9-9 of FIG. 2 andsubstantially along line 9-9 of FIG. 8;

FIG. 10 is a partly transverse sectional, partly isometric view of boththe floor tray illustrated in FIG. 2 and the vehicle foot well surfaceillustrated in FIG. 8, taken substantially along line 10-10 of FIG. 2and substantially along line 10-10 of FIG. 8;

FIG. 11 is a detail of a firewall region of FIG. 10;

FIG. 12 is a detail of a seat pedestal region of FIG. 10;

FIG. 13 is a partly longitudinal sectional, partly isometric view ofboth the floor tray illustrated in FIG. 2 and the vehicle foot wellsurface illustrated in FIG. 8, taken substantially along line 13-13 ofFIG. 2 and substantially along line 13-13 of FIG. 8; and

FIG. 14 is a detail of a kick plate region of FIG. 13.

DETAILED DESCRIPTION

An isometric view of one commercial embodiment is shown in FIG. 1. Theillustrated vehicle floor tray indicated generally at 100 is preferablymolded from a blank, in sheet form, of water-impervious thermoplasticpolymer material having a uniform thickness, although the presentinvention could be fabricated from another process such as injectionmolding. The floor tray 100 is preferably formed of a triextrudedthermoplastic material such that the properties of a central or corelayer can be different than the properties of the external or jacketlayers, and such that the triextrusion is tougher and stiffer per unitthickness than any of the layers from which it is made, as will bedescribed in more detail below.

The vehicle floor tray or cover 100 is meant to protect both the floorand at least the lower sides of a vehicle foot well, and thus takes on amuch more three-dimensional shape than is typical of prior art floormats. The floor tray 100 includes a floor or central panel 102, which inthe illustrated embodiment includes a plurality of fore-to-aft orlongitudinal parallel straight channels 104 that are disposed in aforward region 106 of the floor panel 102. Preferably these channels areabout an eighth of an inch deep so that they will correctly channelrunoff, and can be about one-quarter of an inch wide. In FIG. 1, forwardis a direction to the upper left, while rearward is the direction to thelower right, and the terms are used in conformance with the orientationof the vehicle in which the tray is designed to be placed. As usedherein, “longitudinal” means for-and-aft or along the axis of vehicletravel, while “transverse” means at a ninety degree angle to such anaxis, or side-to-side.

A rearward or back region 108 of the floor panel 102 is largely occupiedby a reservoir 110, whose bottom is made up by a substantially planargeneral surface 112. General surface 112 is situated to be below ageneral surface 114 of the forward region 106. Preferably, the generalbottom reservoir surface 112 is also below the bottommost points of therespective channels 104, as by about one-eighth of an inch, so thatfluid in the channels 104 will empty into the reservoir 110.

The channels 104 are designed to channel liquid runoff from the user'sfeet or footwear to the reservoir 110. In many vehicles, the portion ofthe vehicle floor (not shown in this Figure; see FIGS. 8-11) whichunderlies the forward region 106 slopes from front to rear, and thus thetray 100, by simply conforming to the contour of the underlying vehiclefloor portion, will channel fluid to the reservoir. For those vehicledesigns in which the underlying vehicle floor is not pitched in thismanner, the tray 100 can advantageously be designed to create this fluidflow, as by making the material thicker in portion 106 than in portion108, or by giving the bottoms of channels 104 a front-to-rear slope.

The channels 104 occupy most of the forward region 106, although in thisand other commercial embodiments a space 116 on the forward right handside has been left open to receive the foot of the driver that operatesthe accelerator and brake pedals. In the illustrated embodiment, thisspace or clear area 116 is a delimited by a 180 degree arc of a circleof about four inch radius (shown in dashed line). The clear area 116 isprovided so that the relatively deep channels 104 do not catch the heelof the driver's shoe. In other embodiments, the clear area 116 can takeother shapes or positions, so long as the heels of almost all drivers,while operating the brake and accelerator pedals of the vehicle forwhich the particular tray is designed, will rest within its confines.

The reservoir 110 has interspersed within it a plurality of treadsurfaces or baffles 118, which have two purposes. The first purpose isto elevate the shoe or foot of the occupant above any fluid which mayhave collected in the reservoir 110. The second purpose is to preventthis accumulated fluid from sloshing around. To this end, most of thetread surfaces/baffles 118 have both fore-to-aft or longitudinalportions 120 and side-to-side or transverse portions 122. This preventslarge fluid movement in a forward or rearward direction, as wouldotherwise happen during acceleration or braking of the vehicle, and alsolarge fluid movement side-to-side, as when the vehicle is turning.Preferably, each or at least most of the fore-to-aft portions 120 arejoined to respective side-to-side portions. This furthercompartmentalizes and restricts the movement of collected fluid. Fluidin one portion of the reservoir 110 may make its way only slowly andthrough a complicated path to another distant portion of the reservoir110, through channels 124 around the ends of the treads or baffles 118.The reservoir design thus creates a large surface area which promotesevaporation of the fluid, while at the same time restricts fluidmovement prior to such evaporation.

Disposed around the central or floor panel 102 are a series ofupstanding side panels, which will vary in number and configuration fromone vehicle model to the next. In the illustrated embodiment theseupstanding panels include a back panel 130 that is disposed adjacent thebottom of a vehicle front seat, or a vehicle pedestal for receivingsame; an inner side panel 132 that closely fits a transmission tunnel or“hump” in this vehicle; a forward panel 134 that closely conforms to avehicle firewall; and an outer side panel 136. In most embodiments, theouter side panel or kick plate panel 136 will only extend from itstransition with panel 134 to a corner 138, at which point there begins adoor sill curve 208 which transitions into a door sill panel 140. Unlikethe other panels, the sill panel 140 is not generally upstanding butinstead conforms to the sill of a vehicle door and lies in asubstantially horizontal plane. In this way occupant ingress and egressis not occluded. In many embodiments, including the illustratedembodiment, the sill panel 140 is at an elevation below that of thegeneral surface 114 of the floor forward region 106 and even below thegeneral surface (bottom) 112 of the reservoir 110. Very large amounts offluid (in excess of the reservoir capacity) may therefore flow right outof the vehicle without having the opportunity to damage the vehicleinterior. It should be noted that in these FIGUREs, the lines dividingthe panels are conceptual only and do not appear in the final part. Aswill be described in further detail below, the tray 100 preferably isintegrally molded as a one-piece construction.

In one important aspect of the invention, the tray 100 is closely fittedto the vehicle foot well in which it is designed to be placed. Panels130, 132, 134, 136 and 140 are all formed so as to as closely conform tothe vehicle surfaces against which they are positioned, to an extent notfound in prior art vehicle floor trays. In a preferred embodiment, atleast throughout the top one-third of the areas of these panels that isadjacent a vehicle tray top margin 150, at least ninety percent of thepoints on the outer surface of the peripheral or side panels 130-136 areno more than about one-eighth of an inch from the corresponding pointson the surfaces that they are formed to mate with. This closeconformance occurs even where the underlying vehicular surface iscomplexly curved or angled. Certain portions of the vehicle foot wellsurface, such as kick plate transition plate 214, can have both convexlyand concavely curved elements. The preferred tolerance of door sillcurve 208 and sill plate 140 is even tighter, about 0.025 in.

The close conformance of the tray side panels to respective surfaces ofthe vehicle foot well produces a protective tray which will not behorizontally displaced under lateral forces created by the occupant'sfeet, or by the motion of the vehicle. Opposing pairs of the peripheralpanels “nest” or “cage” the tray 100, preventing its lateral movement.Thus, outer side panel or kick plate panel 136, which closely conformsto a vehicle side wall at that position, has as its counterpart aportion 142 of the inner side panel 132. Any tendency of the tray 100 toshift leftward is stopped by panel 136; any tendency of the tray 100 toshift rightward is stopped by panel portion 142. In a similar manner,the upstanding rearward and forward panels 130 and 134 cooperate to“cage” any forward or rearward motion of the tray 100 within the vehiclefoot well.

The close conformance of the outer or lower surfaces of panels 130-136,218, 140 to their respective mating surfaces of the vehicle foot wellalso increases the frictional force which will oppose any lateralmovement. The result of this close conformance is to provide a floortray which will not undesirably shift position, and which will provide asteady and sure rest to the feet of the occupants.

In most commercial embodiments of the vehicle floor tray 100, the sidepanels 130-136, 140 will not be formed to abruptly extend from thebottom panel 102, but rather will be joined to the bottom or centralpanel 102 through transitions. These transitions may be sloped or curvedand will have a varying degree of gradualness. According to theinvention, the transitions between the outer and bottom surfaces of thetray 100 conform wherever possible to underlying surfaces of the vehiclefoot adjacent these transitions.

In FIG. 2, for example, there is seen a large transition or subpanel 200which extends from forward portion 106. A further subpanel 202 joinstransitional subpanel 202 to the forward sidewall 134. Inner ortransmission tunnel sidewall 132 is joined to the pan 102 through acurved transitional fillet 204. The rear upstanding panel 130 is joinedto the rear portion of bottom panel 102 through a small transition 206.A transition or sill curve 208 between the outer sidewall 136 and thesill panel 140 takes the form of a gradual curved surface.

The present invention also employs (typically) curved transitionsbetween adjacent side panels. For example, a curved transition 210 joinsthe back panel 130 to the inner side panel 132. A curved transition 212joins the transmission tunnel or inner side panel 132 to the front orfirewall panel 134. A transition 214, which in this embodiment takes theshape of an S-curve and conforms to a portion of vehicle wheel well,joins the front panel 134 to the outer side panel 136. The closeconformance (preferably to a tolerance of about ⅛ in.) wherever possibleto the transitions of the vehicle foot well surface by the outer surfaceof the tray 100 enhances a close fit.

In the illustrated embodiment, the tray according to the invention hasbeen made by placing a sheet of substantially uniformly thicktriextruded thermoplastic material into a mold and heating the mold.When this process is used, discrete layers having differentcharacteristics can persist into the final product, as will be describedin more detail below. On the other hand, as using this manufacturingprocess it is difficult to provide the channels and reservoir structureaccording to one aspect of the invention while closely conforming thebottom surface 300 (FIGS. 3 and 4) to a mating surface of the vehiclefoot well. In this central area, and according to the preferredmanufacturing process, a departure away from ⅛ in. tolerance must bemade in order to obtain the above-described benefits of fluid flow andretention. But because the side panels 130-136, 140 and their associatedtransitions continue to closely conform to most of the remaining vehiclefoot well surfaces, the tray 100 continues to be locked in one place.

FIGS. 10-14 superimpose a floor tray 100 on a surface 802 of a vehiclefoot well for which the tray is designed according to the invention. Inthe part-isometric, part-longitudinal sectional view seen in FIG. 10, Itcan be seen that on the section taken there is a quite tight conformanceof the lower surface 300 of the tray 100 to the modeled surface 802 ofthe vehicle foot well. As best seen in FIG. 11, the outer surface of thefirewall sidewall 134 stays within one-eighth of an inch of the firewallsurface 826 for at least three-quarters of the length of surface 826 asmeasured from the top margin 150 of the tray. In areas 1000, 1002 and1004 (FIG. 10), the modeled surface 802 of the vehicle foot well isactually above or to the interior to the tray 100. This negativeinterference is tolerable and in some instances is even desirablebecause the surface 802 is that of a vehicle carpet, which can or evenshould be depressed upon the installation of the tray 100 into thevehicle foot well. Such a tight fit is particularly desirable, forexample, in the region of the tray around the accelerator pedal.

FIG. 12 is a detail of FIG. 10 in the area of the seat pedestal and aportion of the reservoir 110. Once again, there is a very tightconformance of the outer surface of the back panel 130 to the modeledseat pedestal surface 828 throughout most of its length on this section,well within ⅛ inch.

FIG. 13 shows a side-to-side or transverse section taken in a relativelyforward location, so as to cut through the kick plate tray and foot wellsurfaces 136, 830 on one side and the tray and foot well transmissiontunnel surfaces 132, 810 on the other. As can be seen, tolerance towithin ⅛ of an inch is maintained at least for the upper one-third ofthe surface area of these mating surfaces. Areas 1000, 1002 (partiallyrepresented in FIG. 13) and 1006 are areas of negative standoff orinterference in which the modeled surface 802 of the vehicle foot wellis positioned interiorly of the vehicle tray 100. As above explained,this mismatch is permissible if held to ⅛ inch or less, and is evendesirable in some points, because the surface 802 is an image of vehiclecarpeting rather than a hard surface.

In FIG. 14, there is seen at 1400 an intentional increase of radius ofthe transition between kick plate panel 136 and bottom wall 102. This isdone because, for the model shown, the foot well kick plate surface 830is both vertical and is relatively deep. Therefore, sidewall 136 needsto have a draft of at least two degrees (and more preferably fivedegrees) relative to the surface 830 to insure that the wall of the tray100 will remain acceptably thick enough at the junction of walls 136,102. The increase of the radius 1400 accomplishes this. Nonetheless,even on this section the outer surface of the kick plate 136 stayswithin one-eighth of an inch of the kick plate surface 830 for at leastone-third of the length, as measured from margin 150.

More generally, at least ninety percent of that top one-third of thesurface area of each sidewall 130-136 that is adjacent the top margin150 stays within ⅛ in. of the vehicle foot well surfaces with which theyare designed to mate. Alternatively, ninety percent of the top one-halfof the outer surface area of all upstanding sidewalls is within this ⅛inch tolerance of respective foot well surfaces. In even a furtheralternative measurement of tolerance, it is preferred that at leastfifty percent of the outer area of the upstanding sidewalls 130-136 bewithin ⅛ inch of the vehicle foot wells to which they correspond,regardless of position relative to the top margin 150.

As best seen in FIGS. 1, 5 and 10, a top margin 150 of the tray 100,which terminates all of the upstanding sidewalls 130, 132, 134, 136 and138, substantially lies in a single plane which is tilted forwardlyupwardly relative to the horizontal plane. The continuous nature of thetop margin 150 means that the produced tray 100 has a higher hoopstrength, and better protects the vehicle carpeting from dirt or mud onthe sides of the occupant's feet. The occupant's feet tend to occupypositions on the forward region 106, but the position of the top margin150 around this region is high, being at least five inches removed fromthe floor of the tray at its greatest separation.

Composition

According to one aspect of the invention, it is preferred that the trayor cover 100 not be of uniform composition throughout, but rather be alaminate having at least three layers which are bonded together. Apreferred composition of the tray 100 is shown in the highly magnifiedsectional detail shown in FIG. 6. In this illustrated embodiment, thetray 100 consists of a top layer 600, a central or core layer 602, and abottom layer 604. All three layers 600-604 preferably consist of one ormore water-impervious thermoplastic polymers, but layers 600 and 604have properties which are at least different from core layer 602 and mayeven have properties which are different from each other. The trilayercover is shown to be a three-dimensional floor tray in the drawings, butcan also be a more two-dimensional floor mat of more limited coverage.Top layer 600 is made from a material selected for its tactileproperties, its relatively high static and dynamic coefficients offriction with respect to typical footwear, and its resistance tochemical attack from road salt and other substances into which it maycome into contact. Top layer 600 preferably includes a major portion ofa thermoplastic elastomer such as VYRAM®, SANTOPRENE® or GEOLAST®, whichare proprietary compositions available from Advanced Elastomer Systems.VYRAM® is preferred, particularly Grade 101-75 (indicating a Shore Ahardness of 75). An upper surface 606 of the top layer 600 may betextured by a “haircell” pattern or the like so as to provide a pleasingtactile feel and visual appearance, as may a lower surface of the bottomlayer 604.

It is preferred that top layer 600 be a polymer blend, in which instancea minor portion of the composition of the top layer 600 is selected forits coextrusion compatibility with core layer 602. A polyolefin polymeris preferred, such as polypropylene or more preferably polyethylene,even more particularly a high molecular weight polyethylene (HMPE). Asused herein, HMPE is a commodity product, available from many sources,and distinguished in the industry from low density polyethylene (LDPE)and high density polyethylene (HDPE) by its approximate properties:

Characteristic LDPE HDPE HMPE Specific Gravity, ASTM D-792 0.918 0.960.95 Tensile Modulus, ASTM D-638, psi 22,500  95,000 125,000 TensileStrength  1,800  4,500 3,600-3,700 @ Yield, ASTM D-638, psi FlexuralModulus, ASTM D-790, psi 225,000 165,000-175,000 Hardness, ASTM D-2240,Shore D 45 66 68

In the above table, the testing methods by which the properties aredetermined are given for the purpose of reproducibility.

Particularly where the thermoplastic elastomer and the polyolefin arerespectively selected as VYRAM® and HMPE, the proportion by weight ofthe thermoplastic elastomer to polyolefin material in layer 600 ispreferably selected to be about 3:1. It has been discovered that somepolyolefin material needs to be present in layer 600 for coextrusioncompatibility with central layer 602, in the instance where a majorportion of the layer 602 is also a polyolefin.

In an alternative embodiment, the thermoplastic elastomer component ofthe top layer 600 may be replaced with an elastomer such as naturalrubber, acryl-nitrile butadiene rubber (NBR), styrene butadiene rubber(SBR), or ethylene propylene diene rubber (EPDM).

In a further alternative embodiment, layer 600 can be an acrylonitrilebutadiene styrene (ABS) blend. ABS is a material in which submicroscopicparticles of polybutadiene are dispersed in a phase of styreneacrylonitrile (SAN) copolymer. For layer 600, the percentage by weightof polybutadiene, which lends elastomeric properties to the material,should be chosen as relatively high.

The core or central layer 602 preferably is composed of a thermoplasticpolymer material that is selected for its toughness, stiffness andinexpensiveness rather than its tactile or frictional properties.Preferably a major portion of it is a polyolefin such as polypropyleneor polyethylene. More preferably, a major portion of the layer 602 iscomposed of HMPE as that material has been defined above.

It is preferred that the central layer 602 be a blend, and in thatinstance a minor portion of layer 602 is composed of a material selectedfor its coextrusion compatibility with top layer 600 (and bottom layer604 described below). In the illustrated embodiment, this minor portionis a thermoplastic elastomer such as SANTOPRENE®, GEOLAST® or VYRAM®.VYRAM® Grade 101-75 is particularly preferred. For layer 602, andparticularly where the polyolefin and the thermoplastic elastomer arerespectively selected as HMPE and VYRAM®, the proportion by weight ofpolyolefin to thermoplastic elastomer is preferred to be about 3:1. Moregenerally, the percentages of the minor portions in layers 600 and 602(and layer 604) are selected as being the minimum necessary for goodcoextrusion compatibility.

In an alternative embodiment, where layer 600 has been chosen as apolybutadiene-rich layer of ABS, layer 602 is chosen as a grade of ABShaving less of a percentage by weight of polybutadiene in it, or none atall (effectively, styrene acrylonitrile copolymer or SAN).

Bottom layer 604 has a lower surface 300 which will be adjacent thevehicle foot well top surface. Typically, this surface is carpeted. Thebottom layer 604 is a thermoplastic polymer material selected for itswear characteristics, as well as its sound-deadening qualities and ayieldability that allows the layer 604 to better grip “hard points” inthe vehicle foot well surface as well as conform to foot well surfaceirregularities. Preferably, a major portion of the layer 604 is composedof a thermoplastic elastomer, such as SANTOPRENE®, GEOLAST® or,preferably, VYRAM®. VYRAM® Grade 101-75 is particularly preferred.

It is preferred that the bottom layer 604 be a polymer blend. In thisinstance, a minor portion of the bottom layer 604 is selected for itscoextrusion compatibility with the core layer 602. Where core layer 602is mostly made of a polyolefin material, it is preferred that apolyolefin be used as the minor portion of the bottom layer 604. Thispolyolefin can be, for example, polypropylene or polyethylene, andpreferably is HMPE. The amount of the minor portion is selected to bethat minimum amount that assures good coextrusion compatibility. Wherethe polyolefin and the thermoplastic elastomer are respectively chosento be HMPE and VYRAM®, it has been found that the thermoplasticelastomer: polyolefin ratio by weight in the layer 604 should be about3:1.

In an alternative embodiment, the thermoplastic elastomer component oflayer 604 may be replaced with a rubber, such as natural rubber, NBR,SBR or EPDM.

In another alternative embodiment, where the central layer 602 has beenselected as ABS or SAN, layer 604 can be selected as a grade of ABSwhich has a higher percentage by weight of polybutadiene in it than incentral layer 602.

Bottom jacketing layer 604 conveniently can have the same composition astop jacketing layer 600, but the two jacketing layers do not have to besimilar. What is important that, where the tray 100 is to be formed as atriextrusion (as is preferred), layers 600, 602 and 604 be sufficientlycompatible that they can be triextruded as a single sheet.

It is preferred that most of the thickness of the tray 100 be made up bythe core layer 602, which is used as the principal structural componentof the tray 100. The core layer 602 has at least minimally acceptabletensile strength, shear strength and high flexural modulus, while at thesame time being significantly less expensive than the thermoplasticelastomer-dominated jacketing layers. The jacketing layers 600 and 604are selected to present good wear surfaces and to have a good resistanceto chemical attack from substances such as road salt. Top layer 600 isselected to exhibit a relatively high coefficient of friction withrespect to typical occupant footwear. The composition of bottom layer604 is selected for its sound-deadening and yieldability qualities.

The total thickness of tray 100 is the sum of dimensions a, b and c. Inthe illustrated embodiment, jacketing layer thicknesses a and c are eachabout 12.5% of the total thickness, while core layer thickness b isabout 75%. In one embodiment, the total thickness of the tray 100 (or,more precisely, of the blank sheet used to mold the tray 100) isapproximately 0.120 inch. Of this, core layer 602 is about 0.09 inch,while jacketing layers 600 and 604 are each about 0.0150 inch. In analternative embodiment, the layer 600 can be made to be appreciablythicker than layer 604, as top surface 606 is a wear surface for theshoes of the occupant and will see more abrasive dirt and more wear thansurface 300 in typical applications. In another alternative embodiment,the thickness of layer 604 may be increased, allowing it to even betterconform to the vehicle foot well surface with which it is designed tomate and to increase sound-deadening.

A preferred embodiment of the present invention combines the highcoefficient of friction, tactile qualities, sound-deadening andyieldability obtainable with a thermoplastic elastomer with the modestcost of a polyolefin. To demonstrate the technical advantages of atriextrusion tray over monoextruded prior art structures, testsmeasuring tensile strength, shear strength, flexural modulus andcoefficient of friction were performed on (1) a triextrusion sheetmaterial made and used according to the invention, (2) a monoextrudedsheet of 75 wt. pct. VYRAM®/25 wt. pct. HMPE, and (3) a monoextrudedsheet of wt. pct. VYRAM®/75 wt. pct. HMPE. The particular tests andtheir results are described below.

The first two tests performed concern static and dynamic coefficients offriction.

Example 1

These tests determined static and kinetic coefficients of friction of asheet of triextrusion material with respect to an object meant toemulate an typical occupant shoe outsole. This “shoe” was composed ofShore A Durometer 60 neoprene rubber, formed as a “sled” measuring 2.5in.×2.5 in.×0.238 in. The “shoes” were drawn across an upper, texturedsurface of a 0.120 in. triextrusion sheet formed according to apreferred embodiment of the invention measuring 4 in.×12 in. accordingto the procedure set forth in ASTM D 1894-01. The triextrusion sheethad, as its top layer, a blend of 75 wt. pct. VYRAM® Grade 101-75/25 wt.pct. HMPE. The core layer was 75 wt. pct. HMPE/25 wt. pct. VYRAM® Grade101-75. The bottom layer was a blend of 25 wt. pct. HMPE/75 wt. pct.VYRAM® Grade 101-75. The bottom and top layers each comprised about12.5% of the sheet thickness while the middle core layer comprised about75% of the sheet thickness. Results are tabulated as follows.

Static Kinetic Test Static Sled Coefficient Kinetic Sled CoefficientNumber Load (g) Weight (g) of Friction Load (g) Weight (g) of Friction 1166 199.9 0.830 189 199.9 0.945 2 155 199.9 0.775 166 199.9 0.830 3 171200.0 0.855 179 200.0 0.895 4 145 199.9 0.725 160 199.9 0.800 5 150199.9 0.750 163 199.9 0.815 Average 0.787 0.857 Std. Dev. 0.054 0.061

Example 2

Five neoprene rubber “sleds” fabricated as above were drawn across a 4in.×12 in. sheet of a single-extrusion 75 wt. pct. HMPE/25 wt. pct.VYRAM® Grade 101-75, according to ASTM D 1894-01. Results are tabulatedbelow.

Static Kinetic Test Static Sled Coefficient Kinetic Sled CoefficientNumber Load (g) Weight (g) of Friction Load (g) Weight (g) of Friction 1157 200.1 0.785 162 200.1 0.810 2 151 200.0 0.755 148 200.0 0.740 3 163200.1 0.815 170 200.0 0.850 4 146 200.1 0.730 148 200.1 0.740 5 154200.1 0.770 155 200.1 0.775 Average 0.771 0.783 Std. Dev. 0.032 0.047

The above tests show that with respect to a typical shoe solecomposition, a material consisting mostly of a thermoplastic elastomerlike VYRAM® exhibits a higher coefficient of friction than a materialconsisting mostly of a high molecular weight polyolefin.

Example 3

These tests compared the tensile strength of a sheet of triextrudedmaterial as above described with a sheet of single-extruded blend ofmaterial consisting of 75 wt. pct. VYRAM®, Grade 101-75, and 25 wt. pct.HMPE, and further with a sheet of a single-extruded blend of material of75 wt. pct. HMPE and 25 wt. pct. VYRAM® Grade 101-75. The testedsingle-extruded VYRAM®-dominated sheet was approximately 0.070 in.thick, while the HMPE-dominated sheet was approximately 0.137 in. thick.The triextrusion sheet was about 0.120 in. thick. The triextrusionsheet, the single-extruded VYRAM®-dominated sheet and thesingle-extruded HMPE-dominated sheet were die-cut into samples having anaverage width of 0.250″. The test performed was according to the ASTM D638-03 testing standard. A cross-head speed of 20 in./min. was used. Theextensiometer was set at 1000% based on 1.0″ gauge length. Samples wereconditioned at 40 hours at 23 Celsius and 50% relative humidity prior totesting at these conditions. Test results are tabulated below.

Tensile Tensile Tensile Strength Stress Modulus Test at Yield Elongationat Break Elongation (Youngs) Number (psi) at Yield (%) (psi) at Break(%) (psi) Tri- 1 1680 24 1530 730 30800 Extrusion 2 1710 21 1610 71030100 3 1700 21 1620 730 32200 4 1740 19 1660 770 32700 5 1690 17 1630700 24400 Average 1700 20 1610 730 30000 Std. Dev. 23 3 48 27 3320 75%Vyram/ 1 1040 53 1400 620 15900 25% HMPE 2 1010 45 1430 630 17100 3 105098 1390 640 17100 4 1010 62 1430 620 16700 5 1030 88 1420 610 17100Average 1030 69 1410 620 16800 Std. Dev. 18 23 18 11 522 75% HMPE/ 1 91963 1130 630 30200 25% Vyram 2 914 61 1110 630 34100 3 925 69 1120 65029500 4 910 67 1110 650 21500 5 912 68 1140 700 24000 Average 916 661120 650 27900 Std. Dev. 6 3 13 29 5060

The above data demonstrate that a triextrusion material according to theinvention exhibits markedly greater tensile strength than athermoplastic elastomer-dominated single-extrusion material. Also ofinterest is that the three-layer laminate exhibited a higher strength atyield and stress at break than the HMPE-dominated material, whileshowing a comparable tensile Young's modulus.

Example 4

Tests were performed on the above three materials for shear strengthaccording to Test Standard ASTM D732-02. In these tests, a 1.00 in. dia.punch was applied to a 2.0 inch square of material until shear wasachieved. The crosshead moved at 0.05 in/min. The test samples werepreconditioned for at least 40 hours at 23 Celsius and 50% relativehumidity, which were the conditions under which the tests wereperformed. Test results are tabulated below.

Thickness Shear Force Shear Sample Name Test Number (in.) (lbf) Strength(psi) Tri-Extrusion 1 0.119 747 2000 2 0.122 783 2040 3 0.119 747 2000 40.121 757 1990 5 0.117 734 2000 Average 754 2010 Std. Dev. 18 19 75%VYRAM/ 1 0.072 423 1870 25% HMPE 2 0.070 416 1890 3 0.073 489 2130 40.072 481 2130 5 0.073 455 1980 Average 453 2000 Std. Dev. 33 126 75%HMPE/ 1 0.135 680 1600 25% VYRAM 2 0.137 688 1600 3 0.134 687 1630 40.136 724 1690 5 0.137 687 1600 Average 693 1620 Std. Dev. 18 39

The above test data show that, as normalized for the differentthicknesses tested, the triextrusion material is similar in shearstrength to the 75% VYRAM/25% HMPE single-extrusion blend, and superiorin shear strength to the 75% HMPE/25% VYRAM® single-extrusion blend.

Example 5

Tests were performed to determine the flexural properties of samples ofa tri-extrusion material of the above-described formulation, a 75 wt.pct. Vyram/25 wt. pct. HMPE material, and a 75 wt. pct. HMPE/25 wt. pct.VYRAM material (in all tests. the thermoplastic elastomer used wasVYRAM® Grade 101-75). The tests were performed according to the ASTMD790-03 test method, Method I, Procedure A. For the tri-extrusion thedimensions of the samples averaged 0.490″×0.0119″×5.00″, the span lengthwas 1.904 in., and the cross-head speed was 0.051 in./min. For the 75%Vyram/25% HMPE material, the dimensions of the samples averaged0.484″×0.072″×5.00″, the span length was 1.152 in., and the cross-headspeed was 0.031 in./min. For the 75% HMPE/25% Vyram material, thedimensions of the samples averaged 0.50″×0.138″×5.00″, the span lengthwas 2.208 in., and the cross-head speed was 0.059 in/min. In all tests,the span-to-depth ratio was 16+/−1:1, the radius of the supports was0.197 in., and the radius of the loading nose was 0.197 in. The testswere performed at 23 Celsius and 50% relative humidity and the samplesconditioned for 40 hours at this temperature and humidity before thetests were performed. Results are tabulated below.

Flexural Stress At Flexural Modulus Sample Test 5% Deflection (tangent*)Name Number (psi) (psi) Triextrusion 1 294 33400 2 317 36000 3 304 335004 318 35700 5 305 33200 Average 308 34400 Std. Dev. 75% Vyram/ 1 23415400 25% HMPE 2 238 16400 3 230 14500 4 225 14300 5 228 14300 Average231 15000 Std. Dev. 5 915 75% HMPE/ 1 508 13000 25% Vyram 2 505 13800 3496 13100 4 497 12900 5 518 13800 Average 505 13300 Std. Dev. 9 444

The asterisk in the table indicates that the reported values werearrived at by computer generated curve fit. These data show that thetriextrusion is significantly stiffer than either monoextruded sheet.Overall, the triextrusion demonstrates superior properties in terms oftensile strength, shear strength and stiffness per unit cross-sectionalarea in comparison with that of any of the layers of materials fromwhich the laminate is made, demonstrating that a triextruded tray or matwill be tougher and stiffer than one made of either monoextruded blendby itself.

Process

FIGS. 7 and 8 provide an overview of a process for making the vehiclefloor trays or covers according to the invention. The vehicle floortrays and covers are custom-fabricated for discrete vehicle models. Atstep 700, points on the vehicle foot well for which the floor tray is tobe manufactured are digitally measured and captured. Preferably thisstep uses a coordinate measuring machine (CMM) which records each of alarge plurality of points on the surface of the vehicle foot well towhich the floor tray is to be fitted. The inventor has found that aFARO® Arm has been efficacious in obtaining these data using a contactmethod. It has been found that laying out points in linear groups, as bymarking the locations to be measured on tape prior to measurement, isefficacious in capturing enough data points to later recreate thesurface of which they are a part.

The data thus collected are stored in a file. The points of surface dataare spaced from each other as a function of the complexity of thesurface on which they reside. Few points of data are needed to establishlarge surface planes. More points of data are used in defining curvedsurfaces, with the density of data points varying according to thesharpness of the curve. In FIG. 8, representative ones of these pointsare shown by small “x's at 800, on a surface 802 that is reconstitutedusing the technique described immediately below. A typical data filewill contain about a thousand points, spread over an imaged foot wellsurface area of about ten square feet.

The CMM data file is imported into a CAD program, which is used by adesigner to reconstitute a vehicle foot well surface from the capturedpoints. First, at step 701 different “lines” of these points areconnected together by B-splines 804. The splines 804, which the CADprogram can automatically generate, are used to estimate all of thepoints on the line other than the captured data points of that line. Thesplines 804 are separated apart from each other as a function of thetopographical complexity of the portion of the surface that they cover.For large flat areas, such as sill plate 806, the splines 804 may beseparated far apart, as a plane between the splines is a good estimateof the surface in that area. For complex or tightly curved areas, suchas sill curve 832 or kick plate transitional area 833, the splines 804are tightly packed together because the surface segments have to besmall in order to reproduce those curved surfaces of the foot well withacceptable accuracy.

Once the splines 804 have been assembled, the designer lofts an areabetween each pair of parallel splines 804 in order to create differentareal segments 808. The “lofting” process proceeds along each of themajor surfaces of the part, piecewise, until that surface is entirelyrecreated. For example, a transmission tunnel sidewall surface 810 isrecreated by lofting an area 812 between a spline 814 to an adjacentspline 816 along the same surface. The designer then lofts the next area818 from spline 816 to spline 820. Next, an area 822 from spline 820 tospline 824 is added, and so forth down the rest of the transmissiontunnel surface 810 until that entire component of the vehicle foot wellsurface has been created. In similar fashion, the other major surfacesare added: a combination firewall/floor area segment 826, a pedestalsidewall 828, a kick plate segment 830, a sill plate curve 832 and thesill plate 806.

The resultant reconstructed vehicle foot well surface 802 is used, atsteps 703-707, 709, 711, to construct a vehicle floor tray that fits thesurface 802 to an enhanced degree of precision. At step 703, thedesigner chooses top and bottom sketch planes, which intersect thesurface 802 at the top and bottom elevations of the tray to be designed.A top sketch plane intersects surface 802 at a locus high up on thesidewalls 810, 828, 830, 832 and 834. This locus is seen in FIG. 1 as atop margin 150 of the upstanding sidewalls 130, 132, 134, 136 and thetransitions between them. In the preferred embodiment, the top sketchplane is tilted and inclines upward in a forward direction. Thisproduces a tray which is deeper near the firewall than it is near theseat, preferably producing a tray that is at least five inches deep atits deepest part. This protects the foot well carpet from the possiblymuddy sides of an occupant's shoes or boots. A bottom sketch plane isdefined to be coplanar with the bottom surface tray sill plate 140,spaced from the vehicle foot well sill plate 806 by a tight tolerance,such as 0.025″. This bottom sketch plane does not intersect theremainder of the structure but is instead projected upward onto thevehicle foot well surface to create a locus that approximates themarginal outline of the floor/firewall segment 826.

At step 704, sidewalls are drawn in to span the top and bottom sketchplanes. These prototypical sidewalls are created by first drawing aplurality of straight lines, each drawn from a point on the upper sketchplane locus to a point on the lower sketch plane locus. Since the uppersketch plane is more extensive and has a different shape from the lowersketch plane, the lateral margins of the upper and lower sketch planesare not congruent, and the straight lines drawn from the upper sketchplane may be canted at various angles to each other. In general, theselines will slope inwardly from the top sketch plane to the bottom sketchplane. The areas in between these lines can be lofted to createpolygonal surfaces of a completed tray solid.

The resultant solid has a planar top surface, nearly planar bottomsurface and sidewalls which make abrupt corners with them. The actualtransitions between the vehicle foot well sidewall surfaces and thefloor are almost always curved, to a greater or lesser extent dependingon the area in question and on the vehicle model. Therefore, at step705, curves are fitted to the reconstructed vehicle foot well surfaceand these curves are substituted in for the previous abrupt angularshapes. The largest of these curves occurs across the firewall 834, toconform to that sloping and typically curved surface rather than to ahorizontal extension of the bottom sketch plane. Curves are also used tomodify the transitions between the floor 102 and the transmission tunnelsurface 132, the kick plate 136, and the seat pedestal sidewall 130.

The above techniques aim to approximate, as closely as possible, theshape of the upstanding sidewalls 810, 828, 830 and 834, to a zerostandoff from the foot well surface. In some instances, the outersurface of the tray 100 may actually extend slightly beyond the imagedside walls of the vehicle foot well (see portions 1000-1006 in FIGS.10-14), creating a negative standoff. This is permissible to some degreebecause the surface to which the tray is being shaped is carpeted andthe pile may be intentionally depressed at certain points.

The door sill 806 and the sill curve 832 typically are hard surfacesthat must comply to close manufacturer tolerances. A vehicle door isdesigned to mate with these surfaces. Because of this it is important tomatch these surfaces carefully, and preferably this is done in thisprocess to a preselected standoff of 0.025 inch.

At step 704, and for certain vehicle models, certain radii of thetransitional surfaces are increased, in an intentional departure fromthe foot well surface. This is done, for example, where the curvedtransition is one from a deep vertical surface to the floor, as mightoccur between a vertical kick plate and firewall surface segments 836,838. See transition 1400 in FIG. 14. This is done to make sure that thepreferred vacuum molding process, which uses a female tool, does notcreate a thin place in the molded part at the deep corners. Where thesidewall surfaces are sloped inward by more than five degrees, suchradiusing is unnecessary.

At step 707, which can be before, during or after steps 704 and 705, thetray solid is additionally modified to take into account irregularitiesin the reconstructed foot well surface. For example, the vehiclecarpeting might have had rolls or wrinkles in it that should not bereproduced in a tray meant to fit the vehicle. This steps also smoothsout those surface irregularities which are artifacts of the surfaceacquisition and reconstruction steps 700-702.

Once a basic shape for the vehicle floor tray has been formed, it ismodified at 709 in order to create the reservoir 110 and channels 104(See FIGS. 1-4). This modification is necessary because, as has beenexplained, while there is a close conformance or mating between most ofthe exterior or lower surfaces of the floor tray on the one hand to theupper or interior surfaces of the vehicle foot well surfaces on theother, there must be a departure from this close conformance in order tocreate the profile needed by the reservoir and channels. In a preferredembodiment, a predetermined file containing the outer surface of thereservoir and channel surface is integrated into the floor of the traysolid. The importation of this design into the floor of the tray solidwill cause a departure from the imaged vehicle surface floor of as muchas ¼ inch in the areas around the reservoir periphery. This departuredecreases as a function of distance from the imported pattern. Theproduced vehicle floor tray will nonetheless fit tightly to the vehiclefoot well, because (1) the floor carpeting will be depressed to agreater extent under the reservoir than in peripheral areas (see, e.g.,region 1004 in FIG. 10), and (2) the upstanding sidewalls continue toclosely conform to the corresponding surfaces of the vehicle foot well.

At step 711, the tray solid developed at steps 703-707, 709 is“shelled”. This means that the solid is carved out to leave a thin layerthat is a uniform thickness (preferably about 0.120-0.125 in.) from theouter surface.

The result is a tray data file 708 that is a complete representation ofboth the upper and lower surfaces of the floor tray, to a precisionsufficient to create only a ⅛ in. departure or less from a large portionof the respective surfaces of the vehicle foot well. This data file,typically as translated into a .stl format that approximates surfaceswith a large plurality of small triangles, is used at 710 to command astereolithographic apparatus (SLA). The SLA creates a solid plasticimage or model of the design by selectively curing liquid photopolymerusing a laser. The SLA is used to determine fit to an actual vehiclefoot well and to make any necessary adjustments.

As modified with experience gained from fitting the SLA, at 712 thevehicle tray data file is used to make a commercial mold for producingthe vehicle floor trays or covers. Triextruded sheets or blanks 714 areplaced in the mold and heated to produce the vehicle floor trays at 716.

Three-dimensional vehicle floor trays for many different vehicle modelscan be quickly and accurately manufactured using this method. The methodcan also be modified to produce double trays, in which a single tray isprovided which covers both driver and passenger vehicle foot wells aswell as the intervening transmission tunnel. The technique can be usedto create other vehicle floor covers as well, such as the liners used inthe cargo areas of minivans and SUVs.

In summary, a novel vehicle floor tray has been shown and describedwhich fits, within tight tolerances, to the vehicle foot well for whichit is created. The floor tray according to the invention includes areservoir and channel system for retaining runoff in a way that will notslosh around in the foot well. By using a triextruded sheet blank, thetray combines the desirable coefficient of friction and yieldabilitycharacteristics of a thermoplastic elastomer, the lower cost of apolyolefin and a toughness that exceeds either material taken alone.

While an illustrated embodiment of the present invention has beendescribed and illustrated in the appended drawings, the presentinvention is not limited thereto but only by the scope and spirit of theappended claims.

1. A process for manufacturing a vehicle floor tray, comprising thesteps of: digitally measuring the three-dimensional position of aplurality of points on a substantially carpeted surface of a vehiclefoot well for which the vehicle floor tray is to be provided; storingsaid points in a memory; using the stored points to construct a model ofthe vehicle foot well surface; using the model of the vehicle foot wellsurface to construct a three-dimensional representation of a vehiclefloor tray; using the stored three-dimensional representation toconstruct a mold for the vehicle floor tray; and manufacturing thevehicle floor tray by molding polymer material in the mold.
 2. Theprocess of claim 1, wherein said step of digitally measuring thethree-dimensional position of the points on the surface of the vehiclefoot well comprises using a coordinate measurement machine (CMM).
 3. Theprocess of claim 1, wherein the step of using the model of the vehiclefoot well surface to construct a three-dimensional representation of avehicle floor tray comprises the substeps of using the model of thevehicle foot well surface to construct a lower surface of the vehiclefloor tray representation; and shelling the lower surface of the vehiclefloor tray representation to create an upper surface of the vehiclefloor tray representation which is displaced by a uniform thickness awayfrom the lower surface of the vehicle floor tray representation.
 4. Theprocess of claim 1, wherein the step of using the storedthree-dimensional representation to construct a mold for the vehiclefloor tray comprises the substeps of using a file derived from thestored three-dimensional representation to command a sterelithographicapparatus (SLA); responsive to the last said substep of using,selectively curing liquid photopolymer in the SLA with a laser; andresponsive to the substep of curing, forming a plastic model of thevehicle floor tray.
 5. The process of claim 1, and further comprisingthe step of modifying the drawn sidewalls of the three-dimensionalrepresentation of the vehicle floor tray to conform at least the uppertwo-thirds of the area of the outer surface of the sidewalls nearest tothe top margin to respective surfaces of the vehicle foot well model,such that through those areas the sidewalls of the vehicle floor tray donot depart from the corresponding surfaces of the vehicle foot well bymore than one-eighth of an inch.
 6. A process for manufacturing avehicle floor tray, comprising the steps of: digitally measuring thethree-dimensional position of a plurality of points on a surface of avehicle foot well for which the vehicle floor tray is to be provided;storing said points in a memory; using the stored points to construct amodel of the vehicle foot well surface, said step of using the storedpoints including the steps of connecting together groups of the storedpoints with B-splines; lofting between the B-splines to create arealsegments of the surface of the vehicle foot well model; using the modelof the vehicle foot well surface to construct a three-dimensional imageof a vehicle floor tray; and manufacturing the vehicle floor tray bymolding polymer material in the mold.
 7. A process for manufacturing avehicle floor tray, comprising the steps of: digitally measuring thethree-dimensional position of a plurality of points on a surface of avehicle foot well for which the vehicle floor tray is to be provided;storing said points in a memory; using the stored points to construct amodel of the vehicle foot well surface; using the model of the vehiclefoot well surface to construct a three-dimensional image of a vehiclefloor tray, said step of using the model including the substeps ofestablishing a top sketch plane to intersect the vehicle foot well modeland to establish a top margin of the vehicle floor tray; establishing abottom sketch plane to be at the lowest elevation of the vehicle floortray image to be created; drawing sidewalls between the top sketch planeand the bottom sketch plane to approximate corresponding sidewalls ofthe vehicle foot well tray; and using the stored three-dimensional imageto construct a mold for the vehicle floor tray.
 8. The process of claim7, and further comprising the step of: tilting the top sketch plane sothat it is at an angle to a floor of the vehicle foot well model, suchthat the produced vehicle floor tray is deeper in a direction toward thevehicle firewall than it is toward a seat of the occupant.